Baseline Left Ventricular Volume and Shape as Determinants of Reverse Remodeling Induced by Surgical Ventricular Reconstruction

Long-term results of surgical ventricular reconstruction and comparison with the Surgical Treatment for Ischemic Heart Failure trial

OBJECTIVE

The role of surgical ventricular reconstruction (SVR) in patients with ischemic cardiomyopathy is controversial. Observational series and the Surgical Treatment of IsChemic Heart failure (STICH) trial reported contradictory results. SVR is highly dependent on operator experience. The aim of this study is to compare the long-term results of SVR between a high-volume SVR institution and the STICH trial using individual patient data.

METHODS

Patients undergoing SVR at San Donato Hospital (Milan) were compared with patients undergoing SVR in STICH (as-treated principle) by inverse probability treatment-weighted Cox regression. The primary outcome was all-cause mortality.

RESULTS

The San Donato cohort included 725 patients, whereas the STICH cohort included 501. Compared with the STICH-SVR cohort, San Donato patients were older (66.0, lower quartile, upper quartile [Q1, Q3: 58.0, 72.0] vs 61.9 [Q1, Q3: 55.1, 68.8], P < .001) and with lower left ventricular end-systolic volume index at baseline (LVESVI: 77.0 [Q1, Q3: 59.0, 97.0] vs 80.8 [Q1, Q3: 58.5, 106.8], P = .02). Propensity score weighting yielded 2 similar cohorts. At 4-year follow-up, mortality was significantly lower in the San Donato cohort compared with the STICH-SVR cohort (adjusted hazard ratio, 0.71; 95% confidence interval, 0.53-0.95; P = .001). Greater postoperative LVESVI was independently associated with mortality (hazard ratio, 1.02; 95% confidence interval, 1.01-1.03). At 4 to 6 months of follow-up, the mean reduction of LVESVI in the San Donato cohort was 39.6%, versus 10.7% in the STICH-SVR cohort (P < .001).

CONCLUSIONS

Patients with postinfarction LV remodeling undergoing SVR at a high-volume SVR institution had better long-term results than those reported in the STICH trial, suggesting that a new trial testing the SVR hypothesis may be warranted.

A combined cellular and surgical ventricular reconstruction therapeutic approach produces attenuation of remodeling in infarcted rats

BACKGROUND

Left ventricular reconstruction (LVR) has been shown to provide transient benefits to the LV structure and function of infarcted hearts; however, long-term results have been disappointing as LVR-induced benefits are typically not sustained. We hypothesized that administration of cardiosphere-derived cells (CDCs), which promote myocardial repair and regeneration, may result in long-term preservation of the beneficial effects of LVR in ischemic cardiomyopathy.

METHODS

Wistar Kyoto rats underwent myocardial infarction (MI) and two weeks later were randomized into 3 groups: in Group 1 (n=9), LVR was performed by plication of the infarcted apex and CDCs were injected in the infarct border zone (IBZ); group 2 animals (n=9) underwent LVR and received vehicle solution in the IBZ; and Group 3 animals (n=10) were injected with vehicle solution in the IBZ without undergoing LVR. Echocardiograms were performed at baseline, 4 days post-apex plication, and at 3 months post-MI.

RESULTS

At baseline, all animal groups had a comparable LVEF, LV end-diastolic volume (EDV) and LV end-systolic volume (ESV). Four days post-LV apex plication, Group 1 and Group 2 animals exhibited comparable significant improvement in EF and comparable significant reduction in LVEDV and LVESV. Three months post-MI, Group 1 animals had a decreased LVEDV, decreased LVESV, less impaired CS, increased peak systolic torsion and increased EF compared to animals in Groups 2 and 3.

CONCLUSION

In infarcted rat hearts, intramyocardial delivery of CDCs in conjunction with LVR resulted in significant and sustained amelioration of LV remodeling and improvement in LV function compared to LVR alone.

Ventricular volume and myocardial viability, evaluated using cardiac magnetic resonance imaging, affect long-term results after surgical ventricular reconstruction

OBJECTIVES

We aimed to investigate the outcomes of surgical ventricular reconstruction (SVR) for ischaemic cardiomyopathy and to identify ideal candidates for this procedure using cardiac magnetic resonance imaging (MRI) studies.

METHODS

We retrospectively examined 50 patients who underwent SVR and were preoperatively evaluated using cardiac MRI from 2004 to 2014. Cine MRI and gadolinium-enhanced MRI were performed to evaluate left ventricular (LV) volume and scarring. The midterm (median, 2.5 years) risk factors of cardiac death or major adverse cardiac events (MACEs) were analysed. Patients were divided into three groups-those with preoperative indexed LV end-systolic volume (LVESVI) of ≤100 ml/m² (Group 1), those with LVESVI of >100 and ≤130 ml/m² (Group 2) and those with LVESVI of >130 ml/m² (Group 3)-and examined.

RESULTS

In total, 17 patients exhibited MACEs at follow-up. Kaplan-Meier analysis showed that the 5-year rate of freedom from MACEs was 66%. The Cox hazard model indicated that preoperative LVESVI was the only significant predictor for MACEs (P = 0.006; hazard ratio, 1.02; 95% confidence interval, 1.01-1.04). Moreover, a significant reduction in LVESVI and an increase in LV ejection fraction (LVEF) were observed early after SVR (preoperative versus postoperative: LVESVI, 110 ± 44 vs 68 ± 28 ml/m², P < 0.001; LVEF, 24.3 ± 10.3 vs 32.0 ± 10.4%, P < 0.001) and at follow-up (LVESVI, 61 ± 28 ml/m², P < 0.001; LVEF, 36.5 ± 11.5%, P < 0.001). Although no difference was observed between the groups at follow-up, LVEF and LVESVI primarily improved in Group 2. LVEF improvement was significantly greater in Group 2 than in Group 1 (%increase in LVEF: Group 1, 6%; Group 2, 18%; P = 0.008). In patients with a preoperative LVESVI of >130 ml/m², the number of non-viable segments was a significant risk factor for MACEs.

CONCLUSIONS

Patients with preoperative LVESVI ranging from 100 to 130 ml/m² had fairly better outcomes, and the percentage improvement in LVEF and the percentage reduction in LVESVI were more pronounced in these patients. Hence, accurate preoperative assessments of LV volume and viability testing using cardiac MRI studies are essential for better stratification of the SVR procedure.

Impact of surgical ventricular reconstruction on sphericity index in patients with ischaemic cardiomyopathy: follow-up from the STICH trial

AIMS

We sought to evaluate associations between baseline sphericity index (SI) and clinical outcome, and changes in SI after coronary artery bypass graft (CABG) surgery with or without surgical ventricular reconstruction (SVR) in ischaemic cardiomyopathy patients enrolled in the SVR study (Hypothesis 2) of the Surgical Treatment for Ischemic Heart Failure (STICH) trial.

METHODS AND RESULTS

Among 1000 patients in the STICH SVR study, we evaluated 546 patients (255 randomized to CABG alone and 291 to CABG + SVR) whose baseline SI values were available. SI was not significantly different between treatment groups at baseline. After 4 months, SI had increased in the CABG + SVR group, but was unchanged in the CABG alone group (0.69 ± 0.10 to 0.77 ± 0.12 vs. 0.67 ± 0.07 to 0.66 ± 0.09, respectively; P < 0.001). SI did not significantly change from 4 months to 2 years in either group. Although LV end-systolic volume and EF improved significantly more in the CABG + SVR group compared with CABG alone, the severity of mitral regurgitation significantly improved only in the CABG alone group, and the estimated LV filling pressure (E/A ratio) increased only in the CABG + SVR group. Higher baseline SI was associated with worse survival after surgery (hazard ratio 1.21, 95% confidence interval 1.02 - 1.43; P = 0.026). Survival was not significantly different by treatment strategy.

CONCLUSION

Although SVR was designed to improve LV geometry, SI worsened after SVR despite improved LVEF and smaller LV volume. Survival was significantly better in patients with lower SI regardless of treatment strategy.